This is insanely good, from the very start the game knows whats its supposed to be and executes that to perfection right from the main menu. The art, music and gameplay work perfectly together. And as everyone else has been saying the amount of polish is unreal. This is peak.
A very small nitpick would be that sometimes the upgrade text is a litle hard to read but it kinda adds to the charm of the game.
Really great job overall!